Field
The present invention relates to display devices including highly luminescent quantum dots (QDs) comprising a core-shell structure.
Background
Quantum dots (QDs) have the unique ability to emit light at a single spectral peak with narrow line width, creating highly saturated colors. It is possible to tune the emission wavelength based on the size of the QDs. This ability to tune the emission wavelength enables display engineers to custom engineer a spectrum of light to maximize both the efficiency and color performance of the display.
The size-dependent properties of QDs are used to produce a QD film. The QD film may be used as a color down conversion layer in display devices. The use of a color down conversion layer in emissive displays can improve the system efficiency by down-converting white light to a more reddish light, greenish light, or both before the light passes through a color filter. This use of a color down conversion layer may reduce loss of light energy due to filtering.
QDs may be used as the conversion material due to their broad absorption and narrow emission spectra. Because, the density of QDs required for such application is very high in a very thin color down conversion layer of about 3 μm-6 μm, QDs prepared using current methods suffer from quenching of their optical properties when the QDs are closely packed next to each other in a thin QD film. As such, current QD-based display devices using QD films as color down conversion layers suffer from low quantum yield (QY).